The development of Dictyostelium discoideum requires response to extracellular cAMP signalling that is mediated through a family of G protein-linked surface receptors. We had isolated the four members of the cAMP receptor (CAR) family and now determine the spatial regulation of each. The developmental function of CAR4 has been studied in the most detail. CAR4 is a low affinity cAMP receptor that is maximally expressed in prestalk cells and may be required both to establish and to sense the extracellular cAMP signal during late development. Some prestalk cells of car4-null structures are absent or mis-localized. This phenotype is cell autonomous. In contrast, the aberrant patterning of car4-null prespore cells is non-autonomous. Two putative transcriptional regulators of cell fate in Dictyostelium have been identified. One is associated with a mutation that blocks spore differentiation and shares 65% identity with the Brahma-family of regulatory proteins. The other, rfZIP, has a zinc finger and leucine zipper domain. Mutant cells develop poorly and exhibit both cell autonomous and non-autonomous effects on patterning and differentiation. We have also identified promoter sequences for several genes and putative sequence-specific DNA binding proteins that are essential for cell specific-gene expression or response to a distinct intracellular signalling cascade. Lipolysis in mammalian adipocytes requires translocation of hormone sensitive lipase from the cytosol to the lipid droplet surface. Perilipins are located at the droplet surface and are potential regulators of lipolysis. We have constructed cell lines that accumulate lipid droplets without associated perilipin. Analysis of these cells will indicate a potential requirement for perilipin in the activation or inhibition of lipolysis. We have also identified two additional perilipin species and their differential expression in adipogenic and steroidogenic cells. They potentially have distinct regulatory functions in these different cells.